Rolling mill mandrel



R. J. ANATER 2,159,123

ROLLING MILL MANDREL.

Filed Nm 9, 1956 Patented May 23, 1939 UNITED STATES PATENT OFFICE ROLLING MILL MANDREL Jersey Application November 9, 1936, Serial No. 109,973

2 Claims.

This invention relates to flexible couplings and more particularly to a flexible coupling for the mandrel bar and thrust spindle of seamless tube mills although not limited thereto.

In the manufacture of seamless tubes by the Mannesmann or Stiefel process a helical motion is imparted to the workpiece by the rolls rotating it on its axis and at the same time advancing it over a mandrel suitably placed in the path of travel of the workpiece. The forward end of the mandrel carries a piercing point or plug while the rear end is attached to a thrust spindle which permits the mandrel to rotate with the advancing workpiece. Heretofore the common method of attaching the mandrel to the thrust spindle has been by a rigid joint which throws excessive and uncontrollable loads on the thrust spindle bear- It is accordingly an object of the present invention to provide a very efiicient flexible coupling which is cheap and easy to manufacture.

Another object is to provide a joint between the mandrel bar and thrust spindle of a seamless tube rolling mill which will permit universal alignment of the mandrel bar to the thrust spindle and thereby relieve the thrust spindle of excessive loads due to misalignment and permit it to absorb a greater normal thrust load.

The foregoing and other objects will be apparcut after referring to the drawing, in which:

Figure 1 is a plan of the device of the invention as used in connection with a conventional type of seamless type of tube mill;

Figure 2 is an enlarged sectional elevation;

Figure 3 is a sectional view on the line IIIIII of Figure 1; I

Figure 4 is a sectional view on the line IV-- of Figure 2; and

Figure 5 is a fragmentary view on the line V-V of Figure 1.

In the drawing a pair of conventional metal Working rolls are designated by the letter A and the workpiece being acted upon thereby by the letter B. Suitably positioned between the rolls A is a mandrel bar 2 carrying a piercing point or plug C at its forward end 3.

A thrust spindle 5 is flexibly connected to the rear end t of the mandrel bar 2 by a ball and socket joint 6.

Thrust spindle 5 is provided with a concaved hemi-spherical surface I and a cylindrical head or extension 8 is aflixed thereto by welding or other suitable means. The cylindrical head or extension member 8 is provided with a pair of oppositely disposed slots Ill extending throughout the length thereof over an arc of approximately 100 degrees.

A ball shaped head H is attached to the rear end 4 of the mandrel bar '2. This head H is provided with a pair of oppositely disposed slots 5 or cutout portions l2 on its periphery which extend parallel to its longitudinal axis throughout an arc of approximately degrees; thereby pro viding circumferential tongue portions l3 which extend over arcs of approximately 90 degrees. 10 The tongue portions l3 are slightly smaller than the degree slots in of the head 8 so that the ball shaped head H can be readily inserted into the spherical cavity 9 formed by the head 8 and concave surface 1 of the thrust spindle 5. After 15 the head I l is inserted into the cavity $3, the heads 8 and ii are rotated 90 degrees with respect to one another, bringing the slots l8 and 12 into alignment. A suitably shaped key it is then inserted through one of the aligned slots ill and i2 20 and extends into the spherical cavity 9. This key i5 is provided with a dowel pin ll extending outwardly from the end it thereof. A retaining plate or cover it having a slot It to loosely engage the pin ll is secured to the head 8. 25

It will be noted that the thickness 20 of the key i5 is somewhat less than the depth 2! of the slots. ill and I2 and that therefore the keying action is between the radial surfaces 22 of the key it and the radial surfaces 23 of the slots it) and 39 i2 with sufiicient clearance between the inner surface 24 of the key 15 and the outerrsurface 25 of the slot l2 to permit movement of the head H in the hemi-spherical concavity l.

The mandrel bar 2 and thrust spindle 5 may, 35 if desired, be provided with a bore 30 extending therethrough which provides a passageway for the delivery of a cooling fluid to the plug or point C.

While I have shown and described a specific 40 embodiment of my invention it will be under stood that I do not wish to be limited exactly thereto since various modifications may be made without departing from the scope of my invention. 5

I claim:

1. In combination with a seamless pipe or tube mill comprising at least two power-actuated metal-working rolls and an intermediately disposed mandrel, a rotatable compression mandrel 50 bar for supporting said mandrel intermediate said metal-working rolls, a rotatable thrust spindle, and means for flexibly connecting said mandrel bar and said rotatable thrust spindle; said means being adapted for rotation with said ro- 55 tatablemandrel bar and said rotatable thrust spindle and comprisinga ball on one of the connected members, a socket on the other of said connected members, means for permitting the entry and withdrawal of said ball with respect to said socket, and means for connecting said ball and said socket for conjoint rotation.

2. In combination with a seamless pipe or tube mill comprising at least two power-actuated metal-working rolls and an intermediately disposed mandrel, a rotatable compression mandrel bar for supporting said mandrel intermediate said metal-workinglrolls, a rotatable thrust spinsocket on the forward end of said rotatable thrust 7 spindle, means for permitting the entry and withdrawal of said ball with respect to said socket,

and means for connecting said ball and said 0 socket for conjoint rotation.

RAYMOND J. ANATER. 

